Myocardial necrosis is a focal or massive and subsequent scarring and tissue death in the myocardium (heart muscle). It is caused by deficient or total lack of blood supply to the heart muscle, and by infection, such as Histophilus somni, the encephalomyocarditis virus, nutritional deficiency, e.g. vitamin E-selenium, poisoning by plants, e.g. Acacia georgina, farm chemicals, e.g. monensin, and ischemic necrosis due to general or local inadequacy of blood supply to the myocardium. Myocardial necrosis is the death of the cardiomyocytes.